.NET as a whole is what they call "Developer Platform" i.e. Languages + Libraries
.NET can be written in C# , F# or Visual Basic.
C# is one of language in .NET
.NET Core- Win, Mac, Linux
.NET Framework- Websites, Apps for Windows
Xamarin/Mono- .NET for Mobile
Free. Cross-platform. Open source.
A framework for building web apps and services with .NET and C#.
ASP basic Introduction- Reference w3School Old Article
Classic ASP - Active Server Pages Active Server Pages (ASP), also known as Classic ASP, was introduced in 1998 as Microsoft's first server side scripting engine. ASP is a technology that enables scripts in web pages to be executed by an Internet server. ASP pages have the file extension .asp, and are normally written in VBScript. If you want to learn Classic ASP, visit our Classic ASP Tutorial. ASP.NET ASP.NET is a new ASP generation. It is not compatible with Classic ASP, but ASP.NET may include Classic ASP. ASP.NET pages are compiled, which makes them faster than Classic ASP. ASP.NET has better language support, a large set of user controls, XML-based components, and integrated user authentication. ASP.NET pages have the extension .aspx, and are normally written in VB (Visual Basic) or C# (C sharp). User controls in ASP.NET can be written in different languages, including C++ and Java. When a browser requests an ASP.NET file, the ASP.NET engine reads the file, compiles and executes the scripts in the file, and returns the result to the browser as plain HTML. ASP.NET Razor Razor is a new and simple markup syntax for embedding server code into ASP.NET web pages, much like Classic ASP. Razor has the power of traditional ASP.NET, but is easier to use and easier to learn. ASP.NET Programming Languages This tutorial covers the following programming languages: Visual Basic (VB.NET) C# (Pronounced C sharp) ASP.NET Server Technologies This tutorial covers the following server technologies: Web Pages (with Razor syntax) MVC (Model View Controller) Web Forms (traditional ASP.NET) ASP.NET Development Tools ASP.NET supports the following development tools: WebMatrix Visual Web Developer Visual Studio This tutorial uses WebMatrix for Web Pages, and Visual Web Developer for MVC and Web Forms. ASP.NET File Extensions Classic ASP files have the file extension .asp ASP.NET files have the file extension .aspx ASP.NET files with Razor C# syntax have the file extension .cshtml ASP.NET files with Razor VB syntax have the file extension .vbhtml